Abb s203-k5 Miniature Circuit Breaker 5A 3-pole Din Rail

Product Description

The ABB s203-k5 is a 3-pole miniature circuit breaker (MCB) rated for 440 VAC at 5 amps, designed for branch-circuit protection in industrial and commercial electrical distribution systems. It features a K-curve trip characteristic, which provides a delayed response to moderate overloads while tripping quickly under short-circuit conditions — making it suitable for circuits with inductive or transformer loads. The breaker mounts on standard DIN rail and uses screw terminals with arbitrary connection, accepting wire sizes from 18 to 4 AWG. Licensed electricians and panel builders are the primary installers for this device.

The s203-k5 is suited for use in industrial control panels, motor control centers, and commercial power distribution boards operating at 50 or 60 Hz. Its IP20 and IP40 enclosure ratings indicate protection against solid foreign objects in open and enclosed panel environments. The operating temperature range of -25 to 55 degrees C makes it appropriate for both indoor climate-controlled and unheated industrial spaces. The 3-pole configuration handles three-phase circuits in a compact footprint.

Key Features

• K-curve trip characteristic for inductive and transformer load protection
• Interrupt rating of 6 kA and 10 kA depending on configuration
• 3-pole design for three-phase branch-circuit protection
• DIN rail mounting with screw terminals and arbitrary connection
• Accepts 18 to 4 AWG wire sizes
• IP20 and IP40 enclosure ratings for panel and enclosed installations
• Rated for 20,000 operating cycles

Compatibility

Designed as an OEM-style DIN rail-mounted miniature circuit breaker for use in standard IEC-compliant industrial control panels and three-phase commercial distribution systems.

Installation Notes

Installation should be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and any applicable local codes. De-energize the panel and verify the absence of voltage before mounting or wiring this breaker. Secure the unit firmly on a standard 35 mm DIN rail and torque screw terminals per the panel assembly documentation for the specific enclosure. Confirm that the connected load type and fault current levels are compatible with the K-curve trip characteristic and the interrupt rating before commissioning.